Hi,

I am trying to run the open-source Knopflerfish OSGi-Framework on my Asus WL-500d Deluxe router running OpenWRT White Russian RC5.

I installed SableVM, and tested both 1.13 from http://downloads.openwrt.org/backports/rc5/ and 1.11 from http://openwrt.poulpy.org/ with the same results. I can run simple Java programs wihtout problems, but when I run Knopflerfish it crashes after a few minutes. Sometimes I get a Segmentation Fault, sometimes it just gets back to the shell. I increased verbosity of SableVM and Knopflerfish, but I still get no error message before or after the crash.

Does anyone have similar problems or know how to circumvent this?

At the beginning I thought my device didn't have enough memory, so I created a 128MB Swap-file on a USB-Stick, but it didn't help.

I also tried JamVM (from http://downloads.openwrt.org/people/nbd/ar7/packages/) but it just gives me a Segmentation Fault, even if I run it without parameters.

Anyone got Blackdown or Kaffe VM running on their routers? Or any other Java VM?

Thanks in advance
Leonardo.

You probably lack a full classpath package. Anyway, I don't think running heavy Java programs on such device is possible.

Hi,

I am using sablevm-classpath-full: the name suggests it is a full classpath package. As long you have enough memory, any Java program should run on the router. Swapping will make everything slower, but it should still work.

I suppose there is a problem with threads in SableVM. I found the following bug report:

http://sablevm.org/lists/sablevm-bugs/2 … 00789.html

According to the SableVM documentation there are "3 flavors of threaded interpretation (switched, threaded and inlined)", so maybe compiling SableVM with a different kind of thread interpretation could solve the problem.

Regards
Leonardo.

Hi all,

humaita reports an error ("java/lang/NoClassDefFoundError:java/lang/Thread") that occurred when using JamVM. This error message occurred because the JamVM does not work with the sablevm-classpath package. That is an error in the dependency of the JamVM package. I will fill out a ticket to report this problem  to the openWRT developers as soon as possible.
To use JamVM you need the original CLASSPATH from http://www.gnu.org/software/classpath/.

Dex

Hi,

I would just like to tell you guys that the OSGi Framework from Knopflerfish works using JamVM. When I run the fullblown Knopflerfish OSGi Framework with all default bundles, which are designed for a big and heavy desktop PC, the Router still has 1MB (of 32MB) free RAM. The memory footprint of a minimal OSGi Framework is about 4MB, leaving about 9MB free RAM.

The problems I had with JamVM were mostly because I installed classpath on a usb stick. The classpath libs were on /mnt/disc0_1/usr/lib - since busybox doesn't have ldconfig and the ipkg installer couldn't symlink because of the FAT filesystem on the stick it didn't work. As a workaround I copied the libs to /tmp and linked them to the /lib. After that I could start java programs by running

jamvm -Xbootclasspath/a:"/mnt/disc0_1/usr/local/classpath/share/classpath/glibj.zip" [CLASSNAME]

I did not manage to solve the problems with sableVM. I tried compiling it myself with other thread interpretations but I still got the same problems.

Regards,
Leonardo.

Hi,

Since Bamboo is written in Java, is it easy to port Bamboo into wireless access router, e.g. OpenWRT which mostly written in C/C++? Why? How about some other DHT algorithms, e.g. CAN or Chord implementations?

Thank you very much!

Hi,

I suppose you mean http://bamboo-dht.org/, right?

Since Bamboo already runs on Linux - and OpenWRT is an embedded Linux distribution - it should not be very hard. And as you can see from my post OpenWRT also has a working Java VM.

Why don't you try to cross-compile following this guide:

http://wiki.openwrt.org/BuildingPackagesHowTo

Regards
Leonardo.

Hi,

I mean http://bamboo-dht.org.  Are there a lot of coding work to do in the porting? Do you have any use case examples? I am not very good at Java programming.  How long it would take to complete the porting from Bamboo into OpenWrt?

Thanks!

Hi,

I am not a developer. It could be you can just compile the source code without any modifications, so you would not need to do any coding. It could also be you need to change a lot so the code compiles. Cant' tell.

I would just download the OpenWRT-SDK and try to compile the software.

You can find the source-code of current ports (including patches where needed) here:

http://svn.openwrt.org/openwrt/branches … t/package/

Regards
Leonardo.

Hi Leonardo,

Thanks for your reply.

Since it is ported from Java to C/C++, there might be memory resource used up when running Bamboo. Running Bamboo requires more RAM, probably requires libraries and features that Java VM does not provide...